1. Field of the Invention
The present invention relates to an angular velocity correction device, angular velocity correction method, navigation device, and cellular phone having a navigation function, and for example can be favorably applied to a navigation device that can detect the inclination of a vehicle with an angular velocity sensor.
2. Description of the Related Art
Hitherto, navigation devices have been widely used which are mounted on vehicles or the like that move, calculate the current position based on a GPS (Global Positioning System) signal transmitted from a GPS satellite, and indicate the position of the vehicle and direction for advancing on a map screen.
Now, there are locations on actual roads which divide into multiple roads having mutually different inclinations and the mutual roads are near or overlapping in the horizontal direction, such as on/off ramps of a freeway in a city, for example.
Navigation devices have had difficulty determining the roads during advancing in such locations with only the current position calculated with GPS signals or the like.
Navigation devices have been proposed which use an acceleration sensor, angular velocity sensor, air pressure sensor and the like to calculate velocity and changes and so forth relating to the vertical direction of the vehicle, to select roads during advancing of the roads having mutually different inclinations and altitudes, based on these calculations (e.g. see Japanese Unexamined Patent Application Publication No. 2003-194558).
Also, besides navigation devices, portable electronic devices such as cellular phones for example have been proposed which have measuring functions, map display functions and so forth and mount an angular velocity sensor thereon, whereby roads can be selected during advancing of the roads having mutually different inclinations and altitudes.